1. Field of the Invention
This invention relates generally to drafting equipment, and more particularly is directed towards a new and improved drafting machine providing changeable construction guide lines and ellipse angle information for use in preparing three dimensional views.
2. Description of the Prior Art
In making axonometric projections a draftsman must do a substantial amount of preparation before starting his drawing in order to calculate the various angles and dimensions. As a result, the making of an axonometric projection or perspective view, even with the use of various types of drafting scales, grids, ellipse selectors, oblique line scalers, protractors, guides, and the like, is a time consuming affair. While various types of drafting tables and boards have been available for use by draftsmen making drawings, including boards with underlying grids, visible through transparent drawing material, none of the equipment heretofore available has been capable of providing a wide variety of construction guide and depth of field lines along with associated ellipse angle information for use in preparing drawings on either opaque or transparent material.
Accordingly, it is an object of the present invention to provide a new and improved drafting apparatus for use in preparing a wide variety of axonometric and perspective views in various angles along with ellipse angle data proper to the view being drawn. Another object of this invention is to provide a drafting machine for use particularly in making perspective views, along with a changeable display of typical perspective views showing angle numbers and other relevant data.